Insert for a power tool housing

ABSTRACT

Inserts disposed in a housing of a pneumatically or hydraulically powered tool having a motor adapted to rotate a drive lug in either of first and second rotational directions. The insert is composed of a material resistive to creep and/or stress relaxation. The insert contacts fasteners applying a clamping force to the tool and remove the housing from the load path of the clamping force, thereby reducing the possibility of fluid leaks.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to power tools for applyingtorque to a work piece. More particularly, the present invention relatesto an insert that reduces creep and/or stress relaxation in a housing ofa power tool.

BACKGROUND OF THE INVENTION

Many tools are powered by pneumatic air or hydraulic fluid. Impactwrenches, for example, can use pressurized air to impart torque to awork piece to loosen or tighten the work piece. These tools rely on aclamping force to ensure that the motor disposed in a housing does notleak fluid, such as, for example, air or hydraulic fluid. Fluid leaksnegatively affect output power. Typically, the clamping force is createdby coupling a housing and a nose housing using fasteners, such asscrews. However, with the increased use of plastic components, includinghousings, the ability to maintain the necessary clamping force throughthe life of the tool is compromised due to the occurrence of creepand/or stress relaxation.

Existing pneumatic and hydraulic tools include ribs disposed on a rearportion of the housing to reduce and better distribute stress to preventthe occurrence of creep and/or stress relaxation. However, these ribsincrease the dimensions and weight of the tool. Added weight and sizenegatively affects usability of power tools.

SUMMARY OF THE INVENTION

The present invention relates broadly to an insert, also referred to asa compression limiter, coupled to a housing and adapted to receive afastener that couples to a nose housing. The insert provides sufficientarea to contact a head of the fastener. The insert and nose housing arecomposed of a material that is less susceptible to creep and/or stressrelaxation for the clamping force magnitudes commonly used. For example,the insert and nose housing can be composed of metal, and the housingcan be composed of plastic.

In particular, the present invention broadly comprises a tool having amotor. The tool comprising a nose housing, a housing including anaperture adapted to receive a fastener that is adapted to apply aclamping force, an insert disposed within the aperture and havingopposing first and second sides. The first side is adapted to bedisposed proximal to a head of the fastener, and the second side isadapted to be disposed proximal to the motor.

In another embodiment, the present invention can further broadlycomprise an insert adapted to be disposed in a housing aperture of atool. The insert comprises first and second opposing sides, an insertaperture extending through the insert and that is adapted to receive afastener, and an exterior surface corresponding to the housing aperture.The first side is adapted to be disposed proximal to a head of thefastener that applies a clamping force, and the second side is adaptedto be disposed proximal to a motor of the tool.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of facilitating an understanding of the subject mattersought to be protected, there are illustrated in the accompanyingdrawings embodiments thereof, from an inspection of which, whenconsidered in connection with the following description, the subjectmatter sought to be protected, its construction and operation, and manyof its advantages should be readily understood and appreciated.

FIG. 1 is a perspective view of a tool incorporating an insert,according to an embodiment of the present invention.

FIG. 2 is an exploded, disassembled perspective view of portions of thetool of FIG. 1 .

FIG. 3 is cross-sectional view of a housing of the tool of FIG. 1 ,along line 3-3 of FIG. 1 .

FIG. 4 is a perspective view of an insert, according to an embodiment ofthe present invention.

FIG. 5 is a perspective view of an insert, according to anotherembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiments in manydifferent forms, there is shown in the drawings, and will herein bedescribed in detail, embodiments of the invention, including a preferredembodiment, with the understanding that the present disclosure is to beconsidered as an exemplification of the principles of the presentinvention and is not intended to limit the broad aspect of the inventionto any one or more embodiments illustrated herein. As used herein, theterm “present invention” is not intended to limit the scope of theclaimed invention, but is instead used to discuss exemplary embodimentsof the invention for explanatory purposes only.

The present invention broadly comprises an insert for a housing of powertool, such as, for example, a pneumatic or hydraulically powered impactwrench. The insert is disposed in the housing to contact a fastener usedto apply a clamping force. The insert is composed of a material thatresists creep and/or stress relaxation. This allows for the tool tomaintain the clamping force applied by the fastener over the life of thetool, thereby reducing the possibility of fluid leaks.

Referring to FIGS. 1-5 , a tool 100, such as a pneumatic or hydraulicimpact wrench, includes a housing 102, a trigger 104 disposed adjacentto a handle 106 of the housing 102, and a nose housing 108 adapted tocouple to an end of the housing 102. The trigger 104 can be actuated bya user to cause fluid, such as, for example, pressurized air orhydraulic fluid, from an external supply to operate the tool 100 todrive an output lug 130 in either one of first and second rotationaldirections (e.g., clockwise and counterclockwise). The output lug 130can be coupled to other devices, such as a socket, to apply torque to awork piece, such as, for example, a screw or bolt, in a well-knownmanner. The trigger 104 can be biased such that the user can depress thetrigger 104 inwardly, relative to the tool 100, to cause the tool 100 tooperate, and release the trigger 104, wherein the biased nature of thetrigger 104 causes the trigger 104 to move outwardly, relative to thetool 100, to cease operation of the tool 100.

The housing 102 is adapted to house a motor 132 and includes housingapertures 110 adapted to respectively allow fasteners 112 to passtherethrough. The fasteners 112 extend longitudinally through thehousing 102 and are threadably coupled to the nose housing 108. In anembodiment, the housing 102 is composed of a plastic material. Thehousing 102 is coupled to the nose housing 108 via the fasteners 112.The fasteners 112 collectively apply a clamping force to restrict fluid,such as hydraulic fluid or air, from leaking through joints of the motorand/or an interface between the nose housing 108 and the housing 102. Inan embodiment, a gasket 134 is disposed in the interface between thenose housing 108 and the housing 102.

Inserts 114 are disposed in the housing apertures 110 of the housing 102and have first 120 and second 122 opposing sides and an insert aperture124 sized to allow one of the fasteners 112 to pass therethrough. Theinserts 114 can have a substantially circular cross-section as shown,although the invention is not limited to circular cross-sections andother suitable cross-sections may be used. The cross-section of theinserts 114 has sufficient area to contact a head of the fastener 112.For example, the first side 120 of the insert 114 is adapted to abut thehead of one of the fasteners 114. The second side 122 of the insert 114is adapted to abut the motor 132 (such as an end or other part of acasing of the motor 132), thereby transferring the clamping force fromthe fastener 114 to the motor 132 and removing the housing 102 from theload path of the clamping force. In an embodiment, the inserts 114 arebonded to the housing 102 by heat staking. Other suitable methods forbonding the inserts 114 to the housing 102 can be used. The inserts 114are composed of a material that is resistant to creep and/or stressrelaxation, such as, for example, a metal material. The nose housing 108can also be composed of a material that is resistant to creep and/orstress relaxation, such as, for example, a metal material.

The inserts 114 include an exterior surface 126 that corresponds to aninterior surface of the housing apertures 110. In an embodiment, theinserts 114 include a chamfer 116. The chamfer 116 provides a seat for aseal 118 that can be disposed between the head of the fastener 112 andthe first side 120 of each of the inserts 114. In an embodiment, theseal 118 is an elastomeric O-ring. Referring to FIG. 5 , in anotherembodiment, the insert 214 includes one or more barbs 228 disposed onthe exterior surface 226. The barbs 220 respectively grip an interiorsurface of the housing apertures 110 and restrict the insert 214 frombacking out of the housing aperture 110. The insert 214 may also includethe chamfer 116.

By bonding inserts 114/214 into the housing 102, and disposing the motor132 between the inserts 114/214 and the nose housing 108, the housing102 can be removed from the load path of the clamping force applied bythe fasteners 112. Therefore, the entire load path of the clamping forceis through components composed of a material that is resistive to creepand/or stress relaxation, thereby reducing the possibility for fluidleaks to develop.

As discussed herein, the tool 100 can be a pneumatic tool such as animpact wrench. However, the tool 100 can be any pneumatically orhydraulically powered or hand-held tool, such as a ratchet wrench,torque wrench, impact wrench, drill, saw, hammer, or any other tool.

As used herein, the term “coupled” or “communicably coupled” can meanany physical, electrical, magnetic, or other connection, either director indirect, between two parties. The term “coupled” is not limited to afixed direct coupling between two entities.

The matter set forth in the foregoing description and accompanyingdrawings is offered by way of illustration only and not as a limitation.While particular embodiments have been shown and described, it will beapparent to those skilled in the art that changes and modifications maybe made without departing from the broader aspects of the inventors'contribution. The actual scope of the protection sought is intended tobe defined in the following claims when viewed in their properperspective based on the prior art.

What is claimed is:
 1. A tool having a motor, the tool comprising: anose housing; a housing including an aperture adapted to receive afastener that is adapted to apply a clamping force to couple the nosehousing to the housing; an insert disposed within the aperture, theinsert having opposing first and second sides, wherein the first side isadapted to be disposed proximal to a head of the fastener, and thesecond side is adapted to be disposed proximal to the motor.
 2. The toolof claim 1, wherein the insert includes a chamfer at the first side. 3.The tool of claim 1, wherein each of the nose housing and the insert iscomposed of a material resistant to creep and stress relaxation.
 4. Thetool of claim 1, wherein each of the nose housing and the insert iscomposed of metal.
 5. The tool of claim 1, wherein the housing iscomposed of plastic.
 6. The tool of claim 1, wherein the fastener isthreadably coupled to the nose housing.
 7. The tool of claim 1, furthercomprising a seal disposed between the insert and the head of thefastener.
 8. The tool of claim 7, wherein the seal is an O-ring.
 9. Thetool of claim 1, wherein the insert includes a barb disposed on anexterior surface of the insert.
 10. An insert adapted to be disposed ina housing aperture of a housing of a tool, the insert comprising: firstand second opposing sides, wherein the first side is adapted to bedisposed proximal to a head of a fastener that applies a clamping forceto couple a nose housing to the housing, and the second side is adaptedto be disposed proximal to a motor of the tool; an insert apertureextending through the insert and that is adapted to receive thefastener; and an exterior surface corresponding to the housing aperture.11. The insert of claim 10, wherein the insert is bonded to the housing.12. The insert of claim 10, wherein the first side of the insertincludes a chamfer.
 13. The insert of claim 10, further comprising abarb disposed on the exterior surface.
 14. The insert of claim 10,wherein the insert has a substantially circular cross-section.
 15. Theinsert of claim 10, wherein the insert is composed of a materialresistant to creep and stress relaxation.
 16. The insert of claim 10,wherein the insert is composed of a metal material.